The present invention relates to methods and apparatus for cleaning and/or treating substrates and, more particularly, to methods and apparatus for cleaning and/or treating substrates using CO2.
Integrated circuits (ICs), optoelectronic devices, micromechanical devices and other precision fabrications are commonly formed using thin films applied to substrates. As part of the fabrication process, it is often necessary to remove or clean a portion or all of the thin film from the substrate. For example, in the manufacture of semiconductor wafers including ICs, a thin photoresist layer may be applied to the semiconductor substrate and subsequently removed.
Contaminants removed from surface features of microelectronic substrates after various manufacturing steps (e.g., after post-ion implant, xe2x80x98back end of the linexe2x80x99 (BEOL) cleans, xe2x80x98front end of the linexe2x80x99 (FEOL) cleans, and post chemical mechanical planarization (CMP) steps) vary in nature and composition dramatically. Accordingly, cleaning and treating steps must address these contaminants with the appropriate chemistries and solvents to either react with, ionize, dissolve, swell, disperse, emulsify, or vaporize them from the substrate. As such, a variety of water and solvent-based systems, and dry cleaning processes have been developed to address the broad variety of waste materials.
According to method embodiments of the present invention, a method for cleaning a microelectronic substrate includes placing the substrate in a pressure chamber. A process fluid including dense phase CO2 is circulated through the chamber such that the process fluid contacts the substrate. The phase of the CO2 is cyclically modulated during at least a portion of the step of circulating the process fluid.
According to further method embodiments of the present invention, a method for cleaning a microelectronic substrate includes placing the substrate in a pressure chamber. A process fluid including dense phase CO2 is sprayed onto the substrate in a chamber. The phase of the CO2 is cyclically modulated during at least a portion of the step of spraying the process fluid.
According to further method embodiments of the present invention, a method for cleaning a microelectronic substrate includes providing the substrate in a pressure chamber containing a process fluid including dense phase CO2 such that the substrate is exposed to the CO2. The phase of the CO2 is cyclically modulated by alternating CO2 mass flow between a supply of CO2 and the chamber and between the chamber and a low pressure source. The supply of CO2 is at a higher pressure than the chamber and the low pressure source is at a lower pressure than the chamber.
According to further method embodiments of the present invention, a method for cleaning a microelectronic substrate includes placing the substrate in a pressure chamber. A process fluid including dense phase CO2 is introduced into the chamber such that the process fluid contacts the substrate to thereby clean the substrate. A portion of the process fluid is removed from the chamber. The portion of the process fluid is re-introduced into the chamber.
According to further method embodiments of the present invention, a method for cleaning a microelectronic substrate includes placing the substrate in a pressure chamber. A process fluid including dense phase CO2 is introduced into the chamber such that the process fluid contacts the substrate to thereby clean the substrate. A portion of the process fluid is removed from the chamber. The portion of the process fluid removed from the chamber is distilled to separate CO2 from other components of the process fluid. The separated CO2 is re-introduced into the chamber.
According to further method embodiments of the present invention, a method for cleaning a microelectronic substrate includes cleaning a substrate in a process chamber using a process fluid including CO2. The used process fluid is removed from the process chamber. CO2 is separated from the used process fluid. The separated CO2 is reused in the process chamber or a further process chamber.
According to embodiments of the present invention, an apparatus for cleaning a microelectronic substrate includes a pressure chamber and means for circulating a process fluid including dense phase CO2 through the chamber such that the process fluid contacts the substrate. The apparatus further includes means for modulating the phase of the CO2 while the process fluid is being circulated.
According to further embodiments of the present invention, an apparatus for cleaning a microelectronic substrate using a process fluid including dense phase CO2 includes a pressure chamber. A spray member is operative to spray the process fluid onto the substrate in the chamber. The apparatus further includes means for cyclically modulating the phase of the CO2.
According to embodiments of the present invention, an apparatus for cleaning a microelectronic substrate includes a pressure chamber containing a process fluid including dense phase CO2. A supply of CO2 is fluidly connectable to the chamber. The supply of CO2 is at a higher pressure than the chamber. A low pressure source is fluidly connectable to the chamber. The low pressure source is at a lower pressure than the chamber. Fluid control devices are operable to cyclically modulate the phase of the CO2 in the chamber by alternating CO2 mass flow between the supply of CO2 and the chamber and between the chamber and the low pressure source.
According to embodiments of the present invention, an apparatus for cleaning a microelectronic substrate includes a pressure chamber and a supply of a process fluid including dense phase CO2 fluidly connected to the chamber. A distilling system includes a still fluidly connected to the chamber and operative to separate CO2 from the process fluid. The distilling system is operative to re-introduce the separated CO2 into the chamber or a further chamber.
According to embodiments of the present invention, an apparatus for cleaning a microelectronic substrate includes a process chamber containing a process fluid including CO2 and means for removing used process fluid from the process chamber. The apparatus further includes means for separating CO2 from the used process fluid and means for returning the separated CO2 to the process chamber or a further process chamber for subsequent use.
According to embodiments of the present invention, a process chamber assembly for use with a substrate includes a vessel and a substrate holder. The vessel defines a chamber. The substrate holder has a rotational axis and includes front and rear opposed surfaces. The front surface is adapted to support the substrate. At least one impeller vane extends rearwardly from the rear surface and radially with respect to the rotational axis. The impeller vane is operative to generate a pressure differential tending to hold the substrate to the substrate holder when the substrate holder is rotated about the rotational axis. Preferably, the process chamber assembly includes a plurality of the impeller vanes extending rearwardly from the rear surface and radially with respect to the rotational axis.
According to further embodiments of the present invention, a substrate holder for use with a substrate has a rotational axis and further includes front and rear opposed surfaces. The front surface is adapted to support the substrate. At least one impeller vane extends rearwardly from the rear surface and radially with respect to the rotational axis. The impeller vane is operative to generate a pressure differential tending to hold the substrate to the substrate holder when the substrate holder is rotated about the rotational axis. Preferably, the substrate holder includes a plurality of the impeller vanes extending rearwardly from the rear surface and radially with respect to the rotational axis.
According to method embodiments of the present invention, a method for rotating a substrate holder about a rotational axis includes providing a substrate holder. The substrate holder includes front and rear opposed surfaces. The front surface is adapted to support the substrate. At least one impeller vane extends rearwardly from the rear surface and radially with respect to the rotational axis. The substrate holder is rotated about the rotational axis such that the impeller vane generates a pressure differential tending to hold the substrate to the substrate holder.
According to embodiments of the present invention, a pressure chamber assembly for use with a substrate includes a vessel and a substrate holder assembly. The vessel defines a pressure chamber. The substrate holder assembly includes a substrate holder disposed in the pressure chamber, the substrate holder including a front surface adapted to support the substrate, and a housing defining a secondary chamber. At least one connecting passage provides fluid communication between the front surface of the substrate holder and the secondary chamber. The connecting passage is adapted to be covered by the substrate when the substrate is mounted on the front surface of the substrate holder. A passive low pressure source is fluidly connected to the secondary chamber.
According to further embodiments of the present invention, a pressure chamber assembly for use with a substrate includes a vessel and a substrate holder assembly. The vessel defines a pressure chamber. The substrate holder assembly includes a substrate holder disposed in the pressure chamber, the substrate holder including a front surface adapted to support the substrate, and a housing defining a secondary chamber. A restrictive passage provides fluid communication between the pressure chamber and the secondary chamber. At least one connecting passage provides fluid communication between the front surface of the substrate holder and the secondary chamber. The connecting passage is adapted to be covered by the substrate when the substrate is mounted on the front surface of the substrate holder. A low pressure source is fluidly connected to the secondary chamber.
According to method embodiments of the present invention, a method for holding a substrate to a substrate holder in a pressure chamber includes providing a first pressure in the pressure chamber. A substrate holder assembly is provided including a substrate holder disposed in the pressure chamber, the substrate holder including a front surface adapted to support the substrate, and a housing defining a secondary chamber. At least one connecting passage provides fluid communication between the front surface of the substrate holder and the secondary chamber. The substrate is mounted on the substrate holder such that the substrate covers the connecting passage. A second pressure is provided in the secondary chamber that is lower than the first pressure using a passive low pressure source.
According to further method embodiments of the present invention, a method for holding a substrate to a substrate holder in a pressure chamber includes providing a first pressure in the pressure chamber. A substrate holder assembly is provided including a substrate holder disposed in the pressure chamber, the substrate holder including a front surface adapted to support the substrate, and a housing defining a secondary chamber. A restrictive passage provides fluid communication between the pressure chamber and the secondary chamber. At least one connecting passage provides fluid communication between the front surface of the substrate holder and the secondary chamber. The substrate is mounted on the substrate holder such that the substrate covers the connecting passage. A second pressure is provided in the secondary chamber that is lower than the first pressure.
According to embodiments of the present invention, a pressure chamber assembly for retaining a fluid includes first and second relatively separable casings defining an enclosed chamber and a fluid leak path extending from the chamber to an exterior region. An inner seal member is disposed along the leak path to restrict flow of fluid from the chamber to the exterior region. An outer seal member is disposed along the leak path between the inner seal member and the exterior region to restrict flow of fluid from the chamber to the exterior region. The inner seal member is a cup seal.
According to further embodiments of the present invention, a pressure chamber assembly for retaining a fluid includes first and second relatively separable casings defining an enclosed chamber and a fluid leak path extending from the chamber to an exterior region. An inner seal member is disposed along the leak path to restrict flow of fluid from the chamber to the exterior region. An outer seal member is disposed along the leak path between the inner seal member and the exterior region to restrict flow of fluid from the chamber to the exterior region. The inner seal member is a cup seal. The inner seal member is adapted to restrict flow of fluid from the chamber to the exterior region when a pressure in the chamber exceeds a pressure of the exterior region. The outer seal member is adapted to restrict flow of fluid from the exterior region to the chamber when a pressure in the chamber is less than a pressure of the exterior region.
According to embodiments of the present invention, a pressure chamber assembly for processing a substrate includes a pressure vessel defining an enclosed pressure chamber. A substrate holder is disposed in the pressure chamber and is adapted to hold the substrate. A drive assembly is operable to move the substrate holder. The drive assembly includes a first drive member connected to the substrate holder for movement therewith relative to the pressure vessel and a second drive member fluidly isolated from the first drive member and the pressure chamber. A drive unit is operable to move the second drive member. The drive unit is fluidly isolated from the first drive member and the pressure chamber. The second drive member is non-mechanically coupled to the first drive member such that the drive unit can move the substrate holder via the first and second drive members.
According to further embodiments of the present invention, a pressure chamber assembly for processing a substrate includes a pressure vessel defining an enclosed pressure chamber. A substrate holder is disposed in the pressure chamber and is adapted to hold the substrate. A magnetic drive assembly is operable to move the substrate holder relative to the pressure vessel.
According to further embodiments of the present invention, a pressure chamber assembly for processing a substrate includes a pressure vessel defining an enclosed pressure chamber and an exterior opening in fluid communication with the pressure chamber. A substrate holder is disposed in the pressure chamber and is adapted to hold the substrate. A drive assembly is operable to move the substrate holder relative to the pressure vessel, the drive assembly including a housing covering the exterior opening of the pressure chamber so as to seal the exterior opening.
According to embodiments of the present invention, a pressure chamber assembly includes a pressure vessel and a guard heater assembly. The pressure vessel defines an enclosed chamber. The guard heater assembly includes a guard heater disposed in the chamber and interposed between a surrounding portion of the pressure vessel and a holding volume. The guard heater is adapted to control a temperature of the holding volume. The guard heater is insulated from the surrounding portion of the pressure vessel.
According to some embodiments of the present invention, the guard heater and the surrounding portion of the pressure vessel define an insulating gap therebetween. Preferably, the insulating gap has a width of at least 0.1 mm.
According to some embodiments of the present invention, the guard heater assembly includes a layer of insulating material disposed between the guard heater and the surrounding portion of the pressure vessel. Preferably, the layer of insulating material has a thickness of at least 0.1 mm.
The guard heater assembly may further include a second guard heater disposed in the chamber and interposed between a second surrounding portion of the pressure vessel and the holding volume. The second guard heater is adapted to control the temperature of the holding volume. The second guard heater is insulated from the second surrounding portion of the pressure vessel.
A fluid spray bar may be mounted in the guard heater. A substrate holder may be disposed in the holding volume.
According to embodiments of the present invention, a process chamber assembly for use with a substrate and a flow of process fluid includes a vessel and a spray member. The vessel defines a chamber. The spray member includes at least one spray port formed therein adapted to distribute the flow of process fluid onto the substrate in the chamber. The spray member is operative to rotate about a rotational axis relative to the vessel responsive to a flow of the process fluid out of the spray member through the at least one spray port.
The spray member may include a distribution portion including a distribution channel therein, the at least one spray port extending from the distribution channel to exteriorly of the spray member.
The at least one spray port may extend at an angle with respect to the rotational axis. Preferably, the at least one spray port extends at an angle of between about 5 and 85 degrees with respect to the rotational axis.
The process chamber assembly may include a plurality of the spray ports formed in the spray member.
A bearing may be interposed between the spray member and the vessel to allow relative rotation between the spray member and the vessel.
According to further embodiments of the present invention, a spray member for distributing a flow of process fluid onto a substrate includes a spray member including at least one spray port formed therein adapted to distribute the flow of process fluid onto the substrate in the chamber. The spray member is operative to rotate about a rotational axis responsive to a flow of the process fluid out of the spray member through the at least one spray port.
The spray member may include a distribution channel therein, the at least one spray port extending from the distribution channel to exteriorly of the spray member.
The at least one spray port may extend at an angle with respect to the rotational axis. Preferably, the at least one spray port extends at an angle of between about 5 and 85 degrees with respect to the rotational axis.
The spray member may include a plurality of the spray ports formed in the spray member.
The spray member may include a bar-shaped distribution portion, the at least one spray port being formed in the distribution portion. Alternatively, the spray member may include a disk-shaped distribution portion, the at least one spray port being formed in the distribution portion.
According to method embodiments of the present invention, a method of applying a process fluid to a substrate includes placing the substrate in a chamber of a vessel. A spray member is provided including at least one spray port formed therein. The process fluid is distributed from the at least one spray port onto the substrate. The spray member is rotated about a rotational axis relative to the vessel by flowing the process fluid out of the spray member through the at least one spray port.
Objects of the present invention will be appreciated by those of ordinary skill in the art from a reading of the figures and the detailed description of the preferred embodiments that follow, such description being merely illustrative of the present invention.